In recent years, medical treatment has been performed at sites where surgical operations are difficult or which require low invasiveness to the living body, such as PTCA (Percutaneous Transluminal Coronary Angioplasty). In such a treatment, the distal end portion of a catheter is guided to the vicinity of an angiostenosis by use of a guide wire.
One example of a catheter used for such purpose is described in U.S. Pat. No. 5,951,539. The catheter disclosed in this patent includes an inner layer, an outer layer, a reinforcement layer located between the inner layer and the outer layer, and a marker having a contrast property provided at a distal end portion of the catheter. The marker permits confirmation of the position of the distal end portion of the catheter from outside the living body.
However, the catheter possesses a quite large outside diameter due to the sequential lamination of the inner layer, the outer layer, the reinforcement layer, and the marker. It may thus be difficult for the catheter to pass through a target site with a small inside diameter, for example, an angiostenosis or a peripheral portion of a blood vessel. In addition, the width of the band constituting the marker is relatively large to ensure relatively easy confirmation of the position of the distal end portion of the catheter. However, this may spoil or degrade the flexibility of the distal end portion of the catheter.